The study of the pathological changes underlying the neuropathy of the Syrian hamster with hind leg paralysis will be continued with special emphasis in two areas. The first is an optical, morphometric study of the size and number distribution of myelinated fibers in the roots and peripheral nerves in control and in paralyzed hamsters. The second is an electron microscopic study of the glial axonal interface and the periaxonal space in the roots and peripheral nerve of control and mutant hamsters. As part of the fine structural study, the origin of the Hirano body will be investigated from the point of view of the possible effects of autolysis on the formation of these structures.